On Mon, 2 Jun 2025 15:58:10 GMT, Magnus Ihse Bursie <i...@openjdk.org> wrote:
> I don't think this is a good way. We should not call to shell to make > calculations in the makefiles; if that were needed, it should be done in > configure. However, we are already doing this, or at least something very > similar. Have a look at line 398 in boot-jdk.m4. We set up `OLDEST_BOOT_JDK` > as the oldest JDK from the list in version-numbers.conf. > > That should, I think, match your expectation of N-1. There is always a bit > uncertainty how you want these things to be handled around the version > rollover, and I'm not sure about your use case in those situations. But in > general, the oldest boot JDK will match the version number actually used in > the build as the boot JDK, that is, N-1. > > Now, OLDEST_BOOT_JDK is not exported to make. But that is however: > > ``` > BOOT_JDK_SOURCETARGET="-source $OLDEST_BOOT_JDK -target $OLDEST_BOOT_JDK > -Xlint:-options" > ``` > > which is almost, but not exactly, what you were planning to add. The added > `-Xlint:-options` is harmless afaict, and I think was likely added at some > point due to option mismatch between N and N-1 javac lint support, so I think > it would make sense for you to use it as well. > > So, in essense, my suggestion boils down to that you should only add > `$(BOOT_JDK_SOURCETARGET)` to your command line. I don't know the particulars here, but using `javac -source $OLD -target $OLD ..." is _almost_ never more appropriate than using `javac --release $OLD ..." The `options` warning would be noting the possible use of `--release`. ------------- PR Comment: https://git.openjdk.org/jdk/pull/25494#issuecomment-2931680491
